The present invention relates to the design of electronic imaging devices and system, including electronic image capture and electronic image display. In particular it relates to the design of electronic sensor devices capable of capturing images of multiple formats or multiple aspect ratios of width over height. It also relates to the design of display devices, emissive or non-emissive, working in transmission or reflection modes, for direct view or for projection systems, capable of displaying images of different formats or multiple aspect ratios of width over height.
Examples of electronic sensors that the present invention relates to are Charge Coupled Devices (CCDs) and conventional CMOS image sensors (CIS), as well as to the new CMOS-based image sensors described in WO/02/33755. Examples of electronic displays that the present invention can be applied to, are Liquid Crystal Displays (LCDs), Plasma Displays, Organic Light Emitting Diodes (OLEDs), Liquid Crystals On Silicon (LCOS), Digital Micromirror Device (DMD), etc.
Conventionally, the size and aspect ratio of the imaging device (sensor or display) is fixed as a rectangle that is inscribed inside the image circle generated by a lens or group of lenses. The aspect ratio of that rectangle determines the aspect ratio of the acquired/displayed image. The diagonal of the rectangular imaging system matches the diameter of the image circle, regardless of the aspect ratio.
For the same image circle, and thus for diagonals with the same size, rectangles with different aspect ratios have different horizontal and vertical dimensions. For this reason, any rectangle inscribed in the image circle can only be optimized for one particular aspect ratio. For image handling with an aspect ratio other than the one of the imaging device (sensor or display), it is equivalent to having a rectangular image sensor whose diagonal is different than the diameter of the image circle. That results in the loss of areas of the full image circle as produced by the lens, that normally would not be lost with an imaging device with the desired aspect ratio.
Therefore, with conventional imaging devices, for images with different aspect ratios to be handled under optimal conditions, it is necessary to employ multiple imaging devices with the corresponding aspect ratios, otherwise, the results will be suboptimal.
The importance of this problem has been recognized in U.S. Pat. No. 6,307,683 (Oct. 23, 2001), which tries to solve the problem of multi-format image acquisition through increased complexity of a lens group. However, so far there has been no solution at the level of the imaging device (sensor or display) itself.